This trial is a multinational, multicenter, randomized, open-label, active-controlled clinical trial comparing the safety of aspirin versus vitamin K antagonists (warfarin) as oral antithrombotic therapy during the initial 6 months following tissue valve replacement (aortic or mitral).
Aged ≥ 19 years with successful surgical bioprosthetic valve replacement
Bioprosthetic heart valve in aortic or mitral valve positions, for a day postoperatively
The patient or guardian agrees to the study protocol and the schedule of clinical follow-up, and provides informed, written consent, as approved by the appropriate Institutional Review Board/Ethical Committee of the respective clinical site.
Mechanical valve in any heart valve position
Previous hemorrhagic stroke within the last 3 months
Clinically overt stroke within the last 3 months
Current need for anticoagulation (i.e. atrial fibrillation, deep vein thrombosis)